1. Field of the Invention--This invention relates to a novel method and device for cleaning a spray gun assembly that is contaminated with liquid spray material of any type. The novel cleaning method and cleaning device is especially useful for removing residual rapidly-curing spray paint from all of the inside and outside surfaces of a spray gun assembly.
2. Description of the Prior Art--A spray gun assembly includes a spray gun, a gun cup having an open end for storing liquid spray material, such as spray paint, while the gun is being used and means for operatively connecting the gun cup to the gun. The gun assembly may be of the siphon-feed type, the gravity-feed type, or the forced-feed type.
With any of these types, it is absolutely necessary to thoroughly clean all parts of the assembly of spray material promptly after every use. In an automobile body repair shop, it is common practice to use a spray gun assembly several times in a single day with different paints. Cleaning the spray gun assembly after each use is ordinarily a time consuming and labor intensive task. With the increasing use of catalyzed spray paints, the cleaning problem is aggravated because residual paint in the spray gun assembly cures in a much shorter time than do uncatalyzed paints. Spray paints and spray-painting equipment are described in Automotive Collision Work by Edward D. Spicer, American Technical Society, Chicago, 1972 and Paint & Body Handbook by Don Taylor and Larry Hofer, HP Books, Tucson, Arizona, 1984.
Several devices for cleaning or washing contaminated tools are described in prior patents, for example, U.S. Pat. Nos. 3,416,544 issued to J. Paiva; 4,101,340 issued to B. Rand; 4,108,379 issued to H. J. Talley; 4,443,269 issued to J. A. Capella et al.; 4,561,903 issued to R. L. Blaul; 4,612,025 issued to R. W. Sampey; and 4,630,625 issued to J. A. Capella et al.
Each of these prior devices is relatively bulky and requires considerable hand manipulation of the tools by the operator for carrying out the cleaning. Because of the size of these prior devices, noise generated therein is not well contained. Some of the prior devices include blowers for circulating vapor-laden air in the devices and/or pumps for circulating liquid solvents in the system. The use of such blowers and/or pumps on combustible liquids and vapors is hazardous and requires substantial safety precautions to be taken. In general, these prior devices are not particulary adapted for cleaning spray-gun assemblies, and are especially not adapted for use in automobile body repair shops.